grampa_stang

Just so I have this right..(I think). A/F ratio with low numbers...10-12 = rich, where higher numbers 13-14 = lean.
So my question is on the SCT Xcal II there's an option to adjust the A/F ratio in %'s. If I wanted to lean it
out a little would I adjust plus(+) lets says 5% in the A/F ratio option?

Thanks in advance.

moosestang

+ would be adding fuel. You're not adjusting the air/fuel ratio, you're just adjusting the amount of fuel. The amount of air is a constant, well for the most part you can't change it.

grampa_stang

Excellent...thanks Moose.

GT Bob

You WOULD be adjusting the Air Fuel Ratio by adding (or subtracting) fuel... If you have a set amount of air and change the amount of fuel, you are thereby adjusting the ratio of fuel to air, are you not?

To the OP.... be VERY careful when pulling fuel. Pull too much, and your going to seriously increase your risk of detonation. I cannot advise against doing this enough unless you have a WIDEBAND O2 sensor, or you are getting a ridiculous amount of unburnt fuel in the exhaust, or you plugs are fouling because of rich conditions... Modifying your tune without any way of monitoring the changes is just disaster waiting to happen.

grampa_stang

Well, the exhaust is not burning my eyes and it doesn't smell rich. So,
I'll take your advice and NOT screw around. Thanks.